A case of Cushing's syndrome in a 25-year-old pregnant woman is presented. She was found to have Cushing's syndrome at 12 weeks' gestation, and diagnostic studies were compatible with an adrenal tumor. A transabdominal exploration of both adrenal glands was performed at 16 weeks' gestation and a 7 × 5 × 4 cm benign adrenocortical adenoma was found to involve the right adrenal gland which was extirpated. With continuation of supplemental cortisone acetate the pregnancy was maintained. A 2749 g male infant was delivered uneventfully at term and is normal at 12 months of age. Maternal adrenal function was confirmed postnatally via the standard ACTH Stimulation Test. The diagnostic studies and an approach to the management of such a patient are discussed and the literature is reviewed.